Mechanical and Microstructural Behaviour of Friction Stir Welded Al6061/Cr ₂ O ₃ Metal Matrix Composite

Aluminium metal matrix composite are broadly used in various field like aerospace, marine and automobile application. The application of composites necessitates joining process and its difficult due to different materials. To address the considering difficulties the present study is, Cr₂O₃ was reinforced in Al 6061 matrix in 2 % to 6 % in the incremental step of 2 %. The stir casting method was used to fabricate the composites with 300 rpm stirring speed and the stirring time duration was 3 min throughout the fabrication process. The H13 tool is used for prepared friction stir welded (FSW) joints and tool having 6.7 mm pin diameter and 6 mm pin height. The fabrication process is conducted by 500 rpm and 700 rpm tool rotational speed with 50 mm/min and 60 mm/min welding speed receptively. The atmospheric environmental condition was preferred to perform friction stir welding. The mechanical properties of the welded joint, such as tensile strength (ASTM E8), hardness (ASTM E92) and impact strength (ASTM E23) are investigated. The microstructure of welded joints is analyzed by optical microscope. The sample one composite having high tensile strength, sample two having high impact strength then other samples. Microstructure reviewed that the fracture surface shows Dimple appearance.